Piles are well known to provide support for foundations, piering to lift sunken foundations, or to tie back walls or provide other mounting supports, for example. It is also well known to use piles having helical blades that cut into the ground as the pile is rotationally driven into place. Such systems include an elongated shaft in the form of a solid rod or hollow pipe, to which are mounted one or more helical blades. The proximal or trailing end of the shaft is caused to rotate, such as by application of torque from the shaft of a torque motor driver attached thereto, so as to rotate the helical blades into the ground, like a screw. Examples of helix blade systems are shown in my U.S. Pat. No. 6,058,662, and in U.S. Pat. Nos. 5,171,107; 3,999,391; and 3,810,364, among others. In many cases, the blades are required to be driven into the ground to a depth that is deeper than the length of the shaft supporting the blade or blades. In such cases, a second or extension shaft may be attached at its distal or leading end to the trailing end of the preceding shaft, such as with a socket or collar mounted to the end of one of the shafts and receiving the adjacent end of the other shaft therein. Torque is then applied to the trailing end of the second shaft to thereby rotate the blade deeper into the ground. Successive extension shafts may be used.
It is also well known to displace a column of soil and to fill that column with flowable grout, such as neat cement, as the shaft is drawn down through a body of soil as the helix at the lower end of the shaft is screwed into the soil. Examples are shown in U.S. Pat. Nos. 5,707,180, 6,264,402, and U.S. Patent Application Publication No. 2015/0117960A1 among others. These patents disclose the use of a disc that is fixed to an axial location on the pile shaft, which displaces soil and/or acts as a grout-pushing piston as the pile is driven into place. Other patents disclose the use of ground clearing devices affixed within and amongst the helical blades to displace soil and provide a grout channel. Examples are U.S. Pat. No. 8,926,228 and U.S. Patent Application Publication No. 2017/0218590A1, among others. Other devices have been used where grout is pushed through the hollow pile shaft to extrude through openings at various locations to create a pressurized grout channel around the pile shaft. Examples are shown in U.S. Pat. Nos. 3,243,962, 6,058,662, and 7,338,232, among others.